1. Field of the Invention
The present invention relates generally to methods for fabricating magnetic heads for hard disk drives, and more particularly to magnetic head fabrication methods that include the electroplating of a write gap layer therewithin.
2. Description of the Prior Art
As is well known to those skilled in the art, typical magnetic heads for reading and writing data to magnetic media include two magnetic poles with a write gap layer formed between the two poles. In a data writing process, magnetic flux is caused to pass between the magnetic poles across the write gap, and magnetic data bits are thereby formed on the magnetic media that is disposed proximate the magnetic head. To facilitate accurate subsequent reading of the written data bits, it is important that each data bit be generally rectangularly shaped; that is, with straight, parallel leading and trailing edges. This data bit shape is produced by the write head, and particularly by the shape of the leading and trailing edges of the write gap layer. Therefore, it is important to the efficient functioning of hard disk drive device that the leading and trailing edges of the write gap layer of the magnetic head be straight and parallel to each other.
In standard prior art magnetic head fabrication techniques a plurality of magnetic heads are fabricated upon the surface of a substrate, and the write gap layer is uniformly deposited as a thin film across the entire surface of the substrate utilizing a deposition process such as vacuum sputtering. After the magnetic heads on the substrate are fabricated, the substrate is diced to form individual heads. As a result the deposited write gap layer of each magnetic head has straight parallel leading and trailing edges that produce the desired magnetic bit shape.
The present invention relates to a different magnetic head fabrication method wherein the write gap layer is electroplated utilizing a patterned photoresist. This fabrication method has various advantages over the prior art thin film write gap layer sputtering method; however, it can result in a curvature of the leading and/or trailing edges of the write gap layer. This curvature of the leading and trailing edges of the write gap layer creates a correspondingly curved magnetic data bit upon the surface of magnetic media, which leads to the data recording and reading problems referenced above. Furthermore, in current magnetic head fabrication techniques, where the P2 pole tips are made narrower to increase the disk data areal storage density, this write gap layer curvature becomes an increasingly significant problem.
The present invention solves the curved electrodeposited write gap layer problem by initially fabricating the write gap layer to be wider than the intended final P2 pole tip width. Ion milling the sides of the P2 pole tip structure is then performed to remove the curved outer portions of the write gap layer and to thereby fabricate a P2 pole tip having the desired pole tip width. Specifically, following the electrodepositing of the write gap layer and P2 pole tip thereon, an ion milling step is conducted to remove material from the sidewalls of the P2 pole tip including the write gap layer. The ion milling step is preferably conducted utilizing a broad beam ion milling device that is directed to the surface of the substrate upon which the magnetic heads are being fabricated. Preferably, the ion beam is directed at an angle of approximately 70xc2x0 away from normal to the substrate surface such that milling of the head side surfaces is efficiently accomplished. As a result of the ion milling step the curved edges of the write gap layer are removed, and the P2 pole tip width has thereby been narrowed to its desired dimension. Thereafter, further well known fabrication steps are conducted to complete the fabrication of the magnetic head.
It is an advantage of the magnetic head fabrication method of the present invention that a magnetic head having an electroplated write gap layer including straight, parallel leading and trailing edges has been developed.
It is another advantage of the magnetic head fabrication method of the present invention that a magnetic head having an electrodeposited write gap layer has been developed that produces rectangular magnetic data bits upon magnetic media.
It is a further advantage of the magnetic head fabrication method of the present invention that a single broad beam ion milling step is utilized to simultaneously fabricate a plurality of magnetic heads upon a substrate surface.
These and other features and advantages of the present invention will no doubt become apparent to those skilled in the art upon reading the following detailed description which makes reference to the several figures of the drawings.